Add support for SQL

[ryancurrah]

implement the driver.Valuer and sql.Scanner interfaces to support using Version type as a database field

• sql.Scanner: https://golang.org/pkg/database/sql/#Scanner
• driver.Valuer: https://golang.org/pkg/database/sql/driver/#Valuer

[ryancurrah]

@mattfarina not sure if you have had a chance to take a peek yet. do you see any issues? i tried copying for the most what was done for json

[ryancurrah]

@mattfarina hope all is well. do you think this is a valid enhancement?

[mattfarina]

Sorry for the slow response. I looked this over, looked at package sizing to see how much the new dependencies would add, and some other detail.

This looks acceptable.

[ryancurrah]

All good @mattfarina. Thank you!